remove old readme

reference old readme from repo history, if needed

fix asylumfunk/nodeftpd#8
Add tests for withCwd function
Extend tests for withCwd (handle Windows value for path.sep)
Attempt to fix security issue with withCwd and '../' in paths.

New version of withCwd is commented explaining rational.
Merge pull request #8 from asylumfunk/issue/8

remove old readme